Switch devices designed for controlling one or more control and/or auxiliary circuits of an electrical system are known, which generally comprise a box-like casing having switch contacts therein that are adapted to be connected to the terminals of respective electric circuits for selectively closing/opening them upon actuation of an actuator.
Applications are also known in which these switch devices are connected to an electronic control unit, via one or more data buses, or field buses.
Particularly, in this special configuration each device has internally thereto electronic processing means, generally comprising an appropriately programmed electronic board, which are adapted to transduce the electric signals generated by the action of the switching means into digital signals to be transmitted to the electronic control unit through the field bus.
Conversely, the control unit may send certain signals to the device through the bus and the corresponding electronic board, to control the device, e.g. by controlling the actuation of the switching means, or to send queries and check its operating state and proper operation.
An example of such switch device is disclosed in EP1441580, which relates to a switch device connected to a field bus via a data line.
Particularly, the data line has a first section that extends from the switch device and is connected to a connection socket from which a second section of the data line extends to be connected to the field bus through an interface element.
The main drawback of these arrangements is that, in these prior art switch devices suitable to be connected to a field bus or another data line to communicate with a control unit, the processing means are integrated in their case.
Therefore, each device is designed for a particular use and has to be introduced in a system that uses a predetermined communication protocol.
Therefore, due to the impossibility of converting a switch device to a different application, a different type of device must be provided for each potential application, and this involves apparent problems and higher management and production costs.